225/45/R18 vs 225/40/R18

[pmanson]

Hi All,

I'm picking up a new car tonight which is currently running 225/45/R18s which all need replacing.

I was just wondering what the implications would be of changing those to 225/40/R18s?

I'm guessing the speedo will be slightly out - anything else I should be considering?


Car is an MG ZT...


Cheers,
Phill

[RJB_666]

The speedo will probably be out by the slightest margin, not sure if it will be worth sorting others will know more than me on that. It will be a less comfy ride but if your just buying it you won't know the difference. The other thing would be price. Normally lower profile is more expensive.

[Tsippy]

I changed from 45 to 40 on my rx8, the speedo over-read by about 4mph, that was all

Found that the car handled better too, although that could be purely down to the tyre brand.

Only downside was that there was a big visual difference in size, technically not a lot, but when looking at the car the wheels looked a bit lost in the arches.

[pmanson]

I can save about £35 a corner by going to the 40 profile tyres...

From a quick google it appears that MG recommend 225/40/R18 for winter tyres.

[pmanson]

Tsippy said:

Only downside was that there was a big visual difference in size, technically not a lot, but when looking at the car the wheels looked a bit lost in the arches.

That's my only concern as well that it will end up looking like it's running on rubber bands.

Price wise:

• 4x Falken FK452's 225/45/R18 ~ £455
• 4x Falken FK452's 225/40/R18 ~ £345
• 4x Falken FK452's 235/40/R18 ~ £431